OP, you have handled this much more maturely than many I have seen on here. I have seen people flat out throw fits at the comments thrown.
Other posters, whether or not I agree with what the OP is doing is completely irrelevant (and my opinion is useless as I know nothing of dressage anyhow), however this is not in the critique section and it is not your job to educate her. The concerns have been voiced, I think that it is best to leave it alone for now. She has an instructor, she obviously knows that it is not a decision that has been continued, why continue to reply with the same concerned comments? It's not as if she is doing this every day, simply one time, and has admitted to it being a shy attempt.
I know many say "it's for people reading the thread later". However, that's also irrelevant, as your concerns HAVE already been voiced and anyone reading this later will know.
Back to the OP, you have a very good looking horse on your hands. Do post some pictures for us sometime, doing h/j like you do best okay? Don't be too disheartened. This forum is a tough one to get on with but once you do then we really are pretty good to each other. I would hate to lose one of the more mature newer members, when we get so few of those.
Pssh.I didn't pick up the wrong lead
It's called a counter canter...
...A very advanced maneuver.